The most popular HTML, CSS, and JavaScript framework for developing responsive, mobile first projects on the web.
GitHub Pages examples
Fine examples of projects using GitHub Pages (https://pages.github.com).

Gather, curate, and feature stories of public servants and civic hackers using GitHub as part of their open government innovations
Electron website
A simple, static portal which outlines our open source offerings.
A showcase of projects we've open sourced and open source projects we use
A declarative, efficient, and flexible JavaScript library for building user interfaces.
The Artsy Engineering Open-Source Developers Blog
Can you create something cool without modern tools?